This invention relates to improvements in sealing gaskets, especially for internal combustion engines, and particularly in the sealing of the crankcase of an internal combustion engine to prevent the escape of oil therefrom.
When automotive engines such as V-6 and V-8 automobile engines are opened for servicing, they are thereafter reassembled with an appropriate set of seals and gaskets, typically including head gaskets, intake manifold gaskets, and intake manifold end seals, all of which intersect at each end of the associated block. The points of intersection which are relatively small in area chronically present a sealing problem. The usual solution has been to apply a liberal mass of a tube-applied sealing compound, such as an RTV silicone to stop-up the area, thereby to minimize the possibility of splashing out of oil from the crankcase.
Sealing compounds do not provide a guaranteed seal. Further, if they are omitted, then the possibility of a leak is enhanced resulting in the too-rapid loss of engine lubricant, as well as in the splashing of oil over adjacent parts under the hood, in the dripping of oil on garage floors, and the like.
One solution to the problem of sealing the points of intersection which has reduced the problem has been to apply a sealing bead, as by imprinting a bead of silicone on the portion of the head gasket which meets the intake manifold gasket and intake manifold end seal at the intersection. The bead tends to engage the adjacent parts, thereby to provide a dam or barrier with the end seal to prevent oil from escaping from the crankcase at that zone. However, the sealing bead sometimes fails to accomplish its purpose, in part, apparently, due to the fact that currently available printing processes for applying silicone beads to gaskets do not permit the imprinting of beads to the very perimeter of the gasket. The bead therefore terminates about 1/8" or so from the edge of the gasket. Thus, in some cases, the intersection and engagement between the intersection of the head gasket portion and adjacent end seal fails to provide an effective seal thereat and in the related zone of the intake manifold gasket, thereby permitting oil to escape through the open path between the adjacent sealing elements.
An improved method and means for sealing the point of intersection between the head gasket, intake manifold gasket and intake manifold end seal is therefore highly to be desired.